I took another shot at designing a fixed wing. I don't have any serious plans with it yet. Just a design experiment like my last one wich turned out to be all looks and no efficiency. This one is a flying wing design. And again, I have no clue and need some expert advice. As of now it has a 2.5 meter wingspan run by a 13" pusher prop. I think that may be too small? The cutout for the motor is 40mm, I thought that may cover all the size motors that it could run on. It has an internal front mounted tilt camera similar to my quad design. The slit in the front allows a 17° tilt up and 90° tilt down. I posted lots of pics because it's kinda hard to perceive its form due to its streamlined shape. But don't let the shape fool you, it has a payload bay thats 10cm at its deepest point, 20cm wide and 45 cm long.
I'd like too add that I was inspired to go through with this by very motivating dialogue with Curt Olson who built the Resolution. Great guy, great machine!
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never make a flying wing unless there is a compelling reason that excludes a conventional layout...
the efficiency loss isn't worth it if you are concerned with endurance...
Got some updates :-) for one, YES this is now an official project and this bird WILL fly (i hope) one day :-P
I have made a decision abou the wingspan. It is now 2.35 meters. All my math tells me that plays the best motor/battery/weight symphony for up to 90min flights. I've also solved my ugly control horn problem, the pic should be self explanatory. It will need some hands on experimentation to perfect but it's been done before and will work.
I've split the bird in three pieces and started on the wing structure. I will need to do more research and get some consulting concerning best practices for that though. So consider the wing rib structure very beta.
I've also added a duct to cool the ESC, which is probably silly so don't hesitate to throw tomatoes. But I hope its useful...
Last but not least the payload and motor bay without covering. And some more SFW nakedness.
As with my quad project, I'm always looking for serious collaboration, so if you got skills, money or both, and feel this is worth getting involved with, please hit me up. But please don't bore me, I'm not a kid, no offense, I just mean ... please be serious... and nice ... :-P
I agree with Vladimir,
Take it one step at at a time, start simple and build on your success.
Build a 2/3 scale in foam to work out the balance and the bugs, then when you have it right go for the big one. you can save yourself an expensive mistake.
control horns on the top are a must.
calculate the COG then go + 5 to10% further forward for first flights the short nose can work well, my latest wing has no nose.
start with a sweep angle of approx 20 degrees.
Twist, make the control surface wider at the tip than the root and your twist is built in and adjustable with the trim.
This is a large plane, why not use smaller twin motors and props for safety, contra rotate for no torque reaction and more efficient.
Have fun
I've made some changes and have a question. I've made the ailerons wider, inset the winglets 5°, slimmed them up a bit and some sweep. I put a bit more nose on it and vertically aligned the motor closer to the cg. I've also made the motor cutout larger to allow for thrust line adjustment and widened the camera bit to allow for larger cameras and wider lenses. The total wingspan is now 2.7 meters due to the inset in the winglets. I had to pull them outward a bit in order to maintain clean curves.
I've made some rough weight calculations based on the total surface area, assuming a one piece hollow carbon fiber monobody with different thicknesses. Here is the chart with wingspans including winglets. I would like to know if anyone has any thoughts about if I should go for a smaller wingspan for whatever reasons. I'm trying to stay with a 13" prop and high efficiency. Any input would be greatly appreciated.
Carbon Fiber Thickness : Weight
2.3 Meter Wingspan
0.5mm : 1.2Kg
1.0mm : 1.7Kg
1.5mm : 3.7Kg
2.5 Meter Wingspan
0.5mm : 1.4Kg
1.0mm : 2.0Kg
1.5mm : 4.3Kg
2.7 Meter Wingspan (Current version 1.5 meters without winglets)
0.5mm : 1.7Kg
1.0mm : 2.4Kg
1.5mm : 5.1Kg
Eric, 12-13" prop is correct size for 1,5 meter wing...Or you want to flew with 600W power?
@Carl: Thats pretty much what I've heard. Thanks for your commets.
@Curt: Indeed! Preferably a StarTrek inspired materializer or something :-) But I'd be satisfied with anything that cuts time+cost and gets the job done.
@Dwgsparky: You're correct about the prop, I calculated and a 15" prop is correct for the size. Any idea what range of motors are doable? And you are correct about the control surface as well, I've already corrected that. What you are saying about the winglets is totally new to me. I thought they had to be parallel to the center line.
What do any of you think about adding some dihedral?
This is all valuable information, thanks a million...
Looks Awesome I have O experience with flying wings other than I know the COG has to be close to right on and it is nearly impossible to change the angle of incidence The way you check in an RC plane You take it up high and let it free fall straight down with the controls neutral If the nose pitches up The incidence is to high if it pitches down the incidence is to low if it flies straight down it is right on . The incidence is usually set in a flying wing at the factory .When you are scratch building the incidence is a crap shoot? On a normal plane you can usually tilt the wing to adjust it on a flying wing you might be able to do something as long as you don't get to far from the COG by moving weight for and aft Good Job designing though.There is probably people out there that know . Have a good Day!
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